Using Nielsen's People Meter also will allow measurement of consumption patterns for wireless subscribers beyond their mobile phones. In the fall, Vector will be expanded to include a survey that will gauge popularity of specific mobile programs.

"We're really at this point just giving the carriers and advertisers the size of the mobile market," Herrmann said. "The next step is to produce content rankings of the services consumed on the device itself."

Nielsen also released initial findings on the mobile market. In the first quarter of the year, more than 33 million people ages 12 and older used the mobile Web, while more than 8 million people in that age group viewed mobile video.

Nielsen is the latest entrant in an increasingly crowded sector measuring mobile consumption, a crucial component to a nascent market where such information will be relevant to everything from advertiser negotiations to content acquisition.

Nielsen already does some measurement for the wireless business through its Nielsen Mobile division, including ringtone sales tracking. Nielsen Wireless is the latest development from the company's Anytime Anywhere Media Measurement Initiative, which is dedicated to tracking new digital platforms.

Nielsen Wireless initially was part of a larger Nielsen division, Nielsen Wireless & Interactive Services, which launched last year with video game usage tracking as its first product. But Nielsen plans to spin off that function into a separate unit, Nielsen Games, that also will launch in July.